The top B2B agencies were chosen from a survey of agency entries in January. There are four categories: small, midsize, large and interactive. Winners were selected based on:

Percentage of total B2B business

Revenue growths

Client wins

Innovative work

Expanded services capabilities

"As a Denver interactive agency, we've done quite a bit of research on how B2B buyers operate on the web. We know what kinds of information they look for, how they want it presented, and how they move through the sales cycle. It's exciting to watch our clients grow because of the lead strategies we have put into practice," says Ivy Hastings, VP of Strategy at Fusionbox.